Petroleum extraction method and assembly

Claim 1

In an arrangement for the extraction of bituminous products from underground tar sand deposits, the combination of a string of bore hole units detachably connected in end-to-end relationship and extending through an underground tar sand deposit, said string including a lowermost bore hole unit and several upper bore hole units, each unit including a pair of coaxially arranged inner and outer tube sections defining an annular space between each other, each tube section having vertical slots for the radially inward passage of liquefied bituminous products through both sections into the inner tube section, coupling means at both ends of each upper bore hole unit and at the upper end of the lowermost bore hole unit for interconnecting all of said units as a string, the outer tube section of the lowermost bore hole unit having a pointed and closed lower end, and the inner tube section of the lowermost bore hole unit being closed by a closure plate, each unit carrying a plurality of steam pipe sections positioned in said annular space, extending lengthwise and substantially co-extensive with said tube sections in laterally spaced-apart relation around the circumference of said annular space, detachable coupling means at each end of the steam pipe sections of said upper bore units and at the upper end of the steam pipe sections of the lowermost bore hole unit for interconnecting said pipe sections as continuous pipes, said pipes extending to an above ground location to be connected to a supply of steam under pressure, each pipe section having at least one outlet which is radially outwardly directed relative to the bore hole units, so as to inject steam into the surrounding tar sand desposit all around and along the length of the string to lower the viscosity of the bituminous products and cause its radially inward flow into the inner tube sections of said string, and means to elevate the bituminous products relative to the inner tube sections to an accessible above ground location.

Claim 4

A method of extracting highly viscous petroleum from an underground bituminous deposit, comprising inserting a string of detachably interconnected bore hole units into the ground, each unit including a pair of coaxially arranged tube sections defining an intermediate annular space and having lateral apertures therethrough, feeding pressurized steam along said annular space and outwardly from the lower end of each unit to heat the bituminous deposit and decrease its viscosity, allowing the liquefied petroleum to flow inwardly through said tube sections into the inner tube sections and pumping out the petroleum from said inner tube sections simultaneously with the feeding of steam.

Claim 5

A method of extracting highly viscous petroleum from an underground bituminous deposit, comprising inserting a string of detachably interconnected bore hole units into the ground, each unit including a pair of coaxially arranged tube sections defining an intermediate annular space and having lateral apertures therethrough, feeding pressurized steam along said annular space and outwardly from the lower end of each unit to heat the bituminous deposit and decrease its viscosity, allowing the liquefied petroleum to flow inwardly through said tube sections into the inner tube sections and pumping out the petroleum from said inner tube sections simultaneously with the feeding of steam.